Real-world effectiveness of first-line azacitidine or decitabine with or without venetoclax in acute myeloid leukemia patients unfit for intensive therapy.

BACKGROUND: First-line treatment in patients with acute myeloid leukemia (AML) unfit for intensive therapy is the combination of a hypomethylating agent (HMA) with venetoclax (VEN). However, retrospective data confirming the benefits of this regimen outside of clinical trials have shown conflicting results. METHODS: We performed a multicenter retrospective analysis of outcomes with first-line HMA-VEN versus HMA in AML patients unfit for intensive chemotherapy. RESULTS: A total of 213 patients were included from three German hospitals (125 HMA-VEN, 88 HMA). Median overall survival in the HMA-VEN cohort was 7.9 months (95% confidence interval [CI], 5.1-14.7) versus 4.9 months (3.1-7.1) with HMA. After 1 year, 42% (95% CI, 33-54) and 19% (12-30) of patients were alive, respectively (hazard ratio [HR] for death, 0.64; 95% CI, 0.46-0.88). After adjusting for clinical and molecular baseline characteristics, treatment with HMA-VEN remained significantly associated with both prolonged survival (HR, 0.48; 95% CI, 0.29-0.77) and time to next treatment (HR, 0.63; 95% CI, 0.47-0.85). Patients who achieved recovery of peripheral blood counts had a favorable prognosis (HR for death, 0.52; 95% CI, 0.33-0.84). DISCUSSION: These data align with findings from the pivotal VIALE-A trial and support the use of HMA-VEN in patients unfit for intensive therapy.

Molecular determinants of therapy response of venetoclax-based combinations in acute myeloid leukemia.

Acute myeloid leukemia (AML) is a heterogeneous, highly malignant disease of the bone marrow. After decades of slow progress, recent years saw a surge of novel agents for its treatment. The most recent advancement is the registration of the Bcl-2 inhibitor ventoclax in combination with a hypomethylating agent (HMA) in the US and Europe for AML patients not eligible for intensive chemotherapy. Treatment of newly diagnosed AML patients with this combination results in remission rates that so far could only be achieved with intensive treatment. However, not all AML patients respond equally well, and some patients relapse early, while other patients experience longer periods of complete remission. A hallmark of AML is its remarkable genetic, molecular and clinical heterogeneity. Here, we review the current knowledge about molecular features of AML that help estimate the probability of response to venetoclax-containing therapies. In contrast to other newly developed AML therapies that target specific recurrent molecular alterations, it seems so far that responses are not specific for a certain subgroup. One exception is spliceosome mutations, where good response has been observed in clinical trials with venetoclax/azacitidine. These mutations are rather associated with a more unfavorable outcome with chemotherapy. In summary, venetoclax in combination with hypomethylating agents represents a significant novel option for AML patients with various molecular aberrations. Mechanisms of primary and secondary resistance seem to overlap with those towards chemotherapy.

PDP1 is a key metabolic gatekeeper and modulator of drug resistance in FLT3-ITD-positive acute myeloid leukemia.

High metabolic flexibility is pivotal for the persistence and therapy resistance of acute myeloid leukemia (AML). In 20-30% of AML patients, activating mutations of FLT3, specifically FLT3-ITD, are key therapeutic targets. Here, we investigated the influence of FLT3-ITD on AML metabolism. Nuclear Magnetic Resonance (NMR) profiling showed enhanced reshuffling of pyruvate towards the tricarboxylic acid (TCA) cycle, suggesting an increased activity of the pyruvate dehydrogenase complex (PDC). Consistently, FLT3-ITD-positive cells expressed high levels of PDP1, an activator of the PDC. Combining endogenous tagging of PDP1 with genome-wide CRISPR screens revealed that FLT3-ITD induces PDP1 expression through the RAS signaling axis. PDP1 knockdown resulted in reduced cellular respiration thereby impairing the proliferation of only FLT3-ITD cells. These cells continued to depend on PDP1, even in hypoxic conditions, and unlike FLT3-ITD-negative cells, they exhibited a rapid, PDP1-dependent revival of their respiratory capacity during reoxygenation. Moreover, we show that PDP1 modifies the response to FLT3 inhibition. Upon incubation with the FLT3 tyrosine kinase inhibitor quizartinib (AC220), PDP1 persisted or was upregulated, resulting in a further shift of glucose/pyruvate metabolism towards the TCA cycle. Overexpression of PDP1 enhanced, while PDP1 depletion diminished AC220 resistance in cell lines and peripheral blasts from an AC220-resistant AML patient in vivo. In conclusion, FLT3-ITD assures the expression of PDP1, a pivotal metabolic regulator that enhances oxidative glucose metabolism and drug resistance. Hence, PDP1 emerges as a potentially targetable vulnerability in the management of AML.

The proteogenomic subtypes of acute myeloid leukemia.

Acute myeloid leukemia (AML) is an aggressive blood cancer with a poor prognosis. We report a comprehensive proteogenomic analysis of bone marrow biopsies from 252 uniformly treated AML patients to elucidate the molecular pathophysiology of AML in order to inform future diagnostic and therapeutic approaches. In addition to in-depth quantitative proteomics, our analysis includes cytogenetic profiling and DNA/RNA sequencing. We identify five proteomic AML subtypes, each reflecting specific biological features spanning genomic boundaries. Two of these proteomic subtypes correlate with patient outcome, but none is exclusively associated with specific genomic aberrations. Remarkably, one subtype (Mito-AML), which is captured only in the proteome, is characterized by high expression of mitochondrial proteins and confers poor outcome, with reduced remission rate and shorter overall survival on treatment with intensive induction chemotherapy. Functional analyses reveal that Mito-AML is metabolically wired toward stronger complex I-dependent respiration and is more responsive to treatment with the BCL2 inhibitor venetoclax.

Optogenetic stimulation of Gs-signaling in the heart with high spatio-temporal precision.

The standard technique for investigating adrenergic effects on heart function is perfusion with pharmaceutical agonists, which does not provide high temporal or spatial precision. Herein we demonstrate that the light sensitive Gs-protein coupled receptor JellyOp enables optogenetic stimulation of Gs-signaling in cardiomyocytes and the whole heart. Illumination of transgenic embryonic stem cell-derived cardiomyocytes or of the right atrium of mice expressing JellyOp elevates cAMP levels and instantaneously accelerates spontaneous beating rates similar to pharmacological ß-adrenergic stimulation. Light application to the dorsal left atrium instead leads to supraventricular extrabeats, indicating adverse effects of localized Gs-signaling. In isolated ventricular cardiomyocytes from JellyOp mice, we find increased Ca2+ currents, fractional cell shortening and relaxation rates after illumination enabling the analysis of differential Gs-signaling with high temporal precision. Thus, JellyOp expression allows localized and time-restricted Gs stimulation and will provide mechanistic insights into different effects of site-specific, long-lasting and pulsatile Gs activation.

Peer-mentoring Program during the Preclinical Years of Medical School at Bonn University: a Project Description.

Introduction: To better prepare young medical students in a thorough and competent manner for the ever increasing clinical, scientific, as well as psychosocial requirements, universities should enable a close, personal transfer of experience and knowledge. Structured mentoring programs are a promising approach to incorporate clinical subjects earlier into the preclinical training. Such a mentoring program facilitates the prioritization of concepts from a broad, theory-heavy syllabus. Here we report the experiences and results of the preclinical mentoring program of Bonn University, which was introduced in the winter semester of 2012/2013. Project desciption: The program is characterized by the concept of peer-to-peer teaching during the preclinical semesters of medical school. Regular, voluntary course meetings with different clinical case examples provide students the opportunity to apply knowledge acquired from the basic science curricula; furthermore, a personal contact for advice and support is ensured. Thus, an informal exchange of experiences is made possible, which provides to the students motivational and learning aids, in particular for the oral examination at the end of the premedical semesters as well as for other examinations during medical school. Results: Over the course of the preceding three years the number of participants and the interest in the program grew steadily. The analysis of collected evaluations confirms very good communication between mentors and students (>80%), as well as consistently good to very good quality and usefulness in terms of the mentors' subject-specific and other advice. The overall final evaluation of the mentoring program was always good to very good (winter semester: very good 64.8±5.0%, good 35.2±5.0%, summer semester: very good 83.9±7.5%, good 16.1±7.5%) Summary: In summary, it has been shown that the mentoring program had a positive impact on the development, education and satisfaction of students beginning their preclinical semesters at Bonn University.